Hydrocarbon Retention Prediction Model Segmentation

The patent segments the source rock into two distinct components: organic matter (kerogen) and inorganic matter (rock matrix). Each component is assigned separate porosity values (organic porosity and inorganic porosity) and separate hydrocarbon storage capacities. This segmentation allows the model to track hydrocarbon distribution differently in each component, resolving the underestimation issue by explicitly accounting for storage in both organic and inorganic pores throughout the generation process, not just as a residual after expulsion.

The patent implements a nested structure where hydrocarbon fluid is tracked through multiple storage compartments: first in kerogen (adsorbed phase), then in organic porosity (dissolved phase), then in inorganic porosity (dissolved phase), and finally expelled to reservoir. This nested tracking approach ensures that retained hydrocarbons in both organic and inorganic matrices are captured before expulsion occurs, improving prediction accuracy without requiring an entirely new model framework.

The patent divides the hydrocarbon storage system into separate organic and inorganic compartments, each with its own porosity and capacity parameters. This segmentation enables the model to account for hydrocarbon dissolved in the inorganic rock matrix porosity, which traditional models overlook. The segmented approach directly increases the measured quantity of retained hydrocarbon by capturing it in both matrixes simultaneously.

The patent introduces new parameters to traditional kinetic models: organic porosity (φ_org), inorganic porosity (φ_inorg), adsorption capacity (C_ads), and storage capacity (C储). By adding these parameters to the existing kinetic framework, the model expands its ability to quantify retained hydrocarbon volumes without completely restructuring the generation kinetics, thus improving quantity measurement with controlled complexity increase.

The patent uses established correlations from literature as intermediary relationships to bridge Rock-Eval measurements and porosity properties. Specifically, it applies the correlation φ_org = 0.0032 × (Tmax - 60) for organic porosity and φ_inorg = 0.002 × (Tmax - 60) for inorganic porosity. These intermediary equations translate easily measurable Rock-Eval parameters (Tmax) into the harder-to-measure porosity values, improving determination accuracy while avoiding direct complex porosity measurements.

The patent transforms the output parameters from Rock-Eval pyrolysis (TOC, HI, Tmax) into additional derived parameters (organic porosity, inorganic porosity, adsorption capacity, storage capacity) through mathematical relationships. This parameter transformation allows the model to work with readily available Rock-Eval data while accessing information (porosity, storage capacity) that would otherwise require difficult direct measurements.